Slot cutting machine for continuously advancing strip material



July 28, 1964 c. F. RUPNOW 3,142,216

SLOT CUTTING MACHINE FOR CONTINUOUSLY ADVANCING STRIP MATERIAL Filed Feb. 7. 1961 INVENTOR.

CARL F. RUPNOW gwM-QM I ATTORNEY United States Patent 3,142,216 SLOT CUTTING MACHINE FOR CUNTINUOUSLY ADVANCING fiTRIP MATERIAL Carl F. Rupnow, 204 1st Drive NW., Apt. 15, New Philadelphia, Uhio Filed Feb. 7, 1361, Ser. No. 87,570 2 Claims. (Cl. 83308) This invention relates to the art of punching devices and in particular relates to a device designed to repetitively provide a plurality of equidistant elongate slots in a continuously advancing sheet of strip material.

In the known prior art relating to devices of this character, it has long been known, for example, that an advancing sheet of strip material can be passed between juxtapositioned roller members, with the rollers being respectively provided, on their peripheral edges, with male and female punch dies that punch slots in the strip as it advances therebetween.

The disadvantage attendant to such an operation is that it is mandatory in such cases that there be perfect timing with respect to the relative rotation between the respective rollers so that the male and female dies will be disposed in exact registry with each other at the point of punching impact. In high speed production runs of such sheet material it has been found virtually impossible to consistently maintain the desired mesh or inner engagement between components. A representative patent showing structure of this type is United States Patent 690,521.

It has been discovered that the aforementioned difiiculties can be obviated if the back up or slug wheel of the unit is provided with an endless chip receiving cavity that extends radially inwardly from the peripheral edge and that further has a mouth opening sufficient to receive the projecting punch elements of the punch member during the time that the slot is actually being blanked out.

It has been further found that by making this slot endless and of a width to accommodate the projecting punch element after penetration of the strip material, that the need for synchronization between the two roller elements is obviated, in view of the fact that the punch elements of the punch member can coact with any peripheral edge surface of the back up roll in view of the fact that the mouth opening of the chip or blank receiving cavity is continuously and endlessly positioned underneath the strip just below the point of impact made by the punch elements.

It has been further discovered in such instances that the punching element will be uniformly rotated by virtue of the advancement of the strip, with the result that in most instances no drive mechanism of any type is required. In this regard, it should be noted that when the punch has penetrated the strip material, the advancement of the strip will impart rotational movement to the punch wheel and, accordingly, in the normal instance, the full penetration achieved by the punch also facilitates the continued rotational advancement of the punch member so that the same will repetitively blank out elongate slots at consistently spaced intervals.

It has been further found that if the punching element per se is formed to a special contour as will be described, improved results will be obtained, due to the fact that more efiicient penetration of the strip material will be effectuated as a result of the improved contour of the punching element.

Production of an improved slot cutting mechanism having the above desired characteristics accordingly becomes the principal object of this invention, with other objects of the invention becoming more apparent upon a reading of the following brief specification, considered and interpreted in the light of the accompanying drawings.

Of the drawings:

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FIGURE 1 is a perspective view of the improved slot cutting device shown operating in connection with advancing strip material.

FIGURE 2 is a vertical section, partly broken away and in section and being taken on the lines 22 of FIGURE 1.

FIGURE 3 is a vertical section taken on the lines 3-3 of FIGURE 2.

FIGURE 4 is a perspective view of the improved punch element.

Referring now to the drawings and in particular to FIGURE 1 thereof, the improved slot cutting mechanism, generally designated by the numeral 10, is shown including an upright support housing 20 that rotatably supports a punch member 21 and a slug or back up wheel 22; the arrangement being such that these members 21 and 22 are juxtapositioned for tangential adjacency with the opposed sides of a sheet of advancing strip material 23, with punch elements 24, 24 projecting from the peripheral edge of the wheel 22 so as to form a series of longitudinally spaced slots 25, 25 in the advancing strip material.

Referring now to FIGURES 1 and 2 for a detailed consideration of the support 20, it will be seen that the same includes a base 30 as well as an upright housing 31 that is provided with bores 32 and 33 within which shaft members 34 and 35 may be respectively rotatably journaled by ball bearing units 36 and 37, as clearly shown in FIG- URE 2 of the drawings. The shaft 34 preferably has one projecting end 34a thereof keyed or otherwise secured against rotation with respect to a clutch coupling unit 38 with this clutch coupling unit 38 being rotated in unison with shaft 34 through the medium of the belt 39 that is also played about an appropriate pulley extending from an appropriate power shaft 40. The clutch coupling unit 38 is preferably of the type that includes an outer housing 38a, an inner race 38b, an energizing spring 38c and a plurality of sprags 38d. In this regard, it should be noted that while the shaft 34 will usually be rotated as a result of the coaction with the advancing strip material 23, as will be described, that the clutch coupling unit 38 provides for positive rotation thereof in the event that rotational advancement is not effectively achieved by virtue of the advancing strip material 23. Accordingly, the clutch coupler unit is usually of the overrunning type, with the result that the belt 39 will normally not effectuate-drive of shaft 34 unless the same is rotated below the appropriate speed.

It is also believed manifest that if the punch elements are arranged in closer arcuate arrangement than shown that at least one said punch element will always be in engagement with the strip. In such instances the clutch coupler can be eliminated.

Turning next to a consideration of the punch wheel unit 21 and referring particularly to FIGURE 2, it will be seen that the punch wheel 21 is, in actuality, of segmented construction wherein a punch holder 41 is keyed or otherwise secured to the projecting end 34b of shaft 34, with holder 41 undercut, as at 42, to receive certain contoured portions of a clamping ring 43, and with the usual bolts 44, 44 being employed to clamp the bits 24 in place between the aligned faces of the members 41 and 43, as shown in FIGURE 2. A nut 45 securely retains the hub portion of punch holder 41 in position on shaft portion 34b. In like fashion, the back up or slug wheel 22 is shown being formed of segmented two-part construction, with the same including a main wheel segment 50 having a hub portion 51 that is keyed, or otherwise non-rotatably secured, to the projecting end 35a of shaft 35. An auxiliary wheel segment 52, again of generally circular configuration, is provided with an aperture 53 that likewise is received over the projecting end 35a of shaft 35, with nut 54 serving to clamp the radially 3 innermost axial faces of the wheel members 50 and 52 into abutment with each other as shown in FIGURE 2.

In addition to the aforementioned component parts, the wheels 50 and 52 have their opposed axial faces undercut as at 50a and 52a, respectively, with these axial undercuts serving to define the walls of a chip or blank receiving slot indicated generally by the numeral 56. The chamber or cavity 56 has a reduced mouth opening 57 that preferably extends circumferentially of the wheel member 22 in endless fashion, and in the preferred form of invention the width of the mouth opening 57 is, as shown in FIGURE 2, just slightly greater than the width of an individual punch element 24.

In this fashion, the mouth opening 57 will serve as an endless female die for the punch members 24, 24 which will successively penetrate the strip material 23 as shown in FIGURE 2 and thus effectuate the blanking out of the slot 25. In this regard, the blanked out material, indicated by the numeral 25a in FIGURES 2 and 3, will be received in the chamber 56 but will be almost immediately ejected therefrom at a rotationally advanced point due to the centrifugal force involved during rotation of the wheel 22.

Referring next to FIGURE 4 for a detailed consideration of the punching element 24, it will be seen that the same is of generally rectangular configuration so as to include a top surface 60, a bottom surface 61, a front surface 62, a rear surface 63 and opposed side surfaces 64 and 65.

In the preferred form of the invention shown herein, the top surface 60 is inclined slightly with respect to the bottom surface 61, with the preferred angle of inclination of the planar surface 60 being approximately degrees. This inclination permits the surface 60 to approach the actual impact point in approximate parallelism with the surface 23a of the advancing strip material. The top surface 60 is further contoured as shown in FIGURE 4 to provide an even more effective blanking or cutting instrument. In this regard, the planar surface 60a continuously adjoins a concave undercut 60b, with this concave undercut 60b, in turn, contiguously adjoining a planar surface 6022 that is disposed, in the preferred form of the invention, at approximately 40 degrees to the front edge 62. The planar surface 60b terminates, at the point of juncture with surface 62, in a cutting edge indicated by the numeral 66. While the numeral 66 has been employed to designate a specific edge, it is to be understood that all edges of surface 60 are cutting edges within the broad meaning of the term.

In use or operation of the improved slot cutting device, it will be first assumed that the component parts have been assembled as indicated by the drawings and further that the punch and back up members 21 and 22 have been journaled about parallel axes of rotation so that their peripheral edge surfaces are disposed in tangential adjacency with the opposed sides of the strip material 23. At this time the strip 23 may be started in movement of the direction of the arrow 70 and simultaneously therewith the power shaft 40 will be actuated to cause rotation of shaft 34.

The condition of actual punching is best illustrated in the sectional view of FIGURE 3, and as best shown therein, it will be noted that the rear portion (as viewed in FIGURE 4) of the insert 24 will first strike the surface 23a of the advancing strip material. As the strip continues to advance and the wheel 21 also continues to rotate, the top surface 60 will cause the slot 25 to be blanked out, with the cutting edge 66 finally kicking, or otherwise detaching, the slug 25a from the strip 23, as shown in FIGURE 3. It should be noted in FIGURE 3 that the insert 24 has fully penetrated within the mouth opening 57 so as to firmly drive the severed slug 25a into the confines of the cavity 56. As rotation of the wheel members 21 and 22 continues in the direction of arrows 71 and 72 respectively, the centrifugal force will cause the slug 25a to be ejected approximately degrees from the point of contact with the strip 23. It is to be understood that the exact point of ejection of the slug from the cavity 56 depends upon many factors, including rotational speed.

It will be seen that by virtue of the fact that the insert 24 has fully penetrated the strip 23 in the blanking out of the slot 25, that the same will, in fact, be in positive contact with the wall of the just formed slot. As a result of such wall-to-insert contact, advancement of the strip 23 will rotationally drive the wheel 22 and in production it has been found that the just described blanking operation repetitively and automatically produce slots 25, 25 that are longitudinally equidistant from each other. Thus, while in the normal instance the clutch coupling unit will not come into play, the same is available as an auxiliary drive unit should the advancing strip fail to drive the wheel 22, as just described. It is understood that an equivalent clutch coupling unit 38 could be connected to the shaft 35 to insure rotational drive of the same, although it is to be understood that it is not mandatory that the rotational support of the members 21 and 22 be equal. This is true because of the fact that the slug or back up wheel 22 has, in effect, an endless female die provided in its peripheral edge in the form of mouth opening 57.

It will be seen from the foregoing that there has been provided a new and improved type of slot cutting machine that is characterized by the fact that the same require no synchronization or mesh of any kind between the punch and slug members that have their peripheral edges juxtapositioned adjacent the opposed faces of the advancing strip in substantially tangential adjacency therewith.

It will be further seen how the use of segmented type construction in both of the wheel elements permits ready and rapid adjustment of the distance between the slot members, with such adjustment being possible because of the fact that the clamping ring 43 permits variation in the circumferential spacing of the inserts 24, 24 so that any slot pattern of any desired longitudinal spacing can be achieved without any adjustment whatsoever of the back up or slug wheel 22.

While a full and complete disclosure of the combination has been set forth in accordance with the dictates of the patent statutes, it is to be understood that the invention is not intended to be limited to the specific form herein shown. Thus, while circular wheels having continuous peripheral edges are contemplated, it is to be understood that equivalent spoke-like arrangements could be employed. Similarly, it is contemplated that the inserts 24, for example, could be moved endlessly on a chain or other media through a closed cyclic path that was other than circular.

Accordingly, modifications of the invention may be resorted to without departing from the spirit hereof or the scope of the appended claims.

What is claimed is:

l. A slot cutting device for use with continuously ad- Vancing strip material, comprising:

(A) juxtapositioned punch and back-up members (1) each having endless peripheral edges that are arranged for movement around parallel axes and through closed cyclic paths of movement that respectively include increments of movement that are substantially adjacent the opposed sur faces of said strip ([1) whereby said strip may pass between said punch and back-up members in substantial tangency therewith;

(B) a slug receiving cavity opening radially inwardly from the peripheral edge of said back-up member; (C) at least one punch element (1) carried by said punch member for movement therewith and (2) projecting beyond the peripheral edge of said 5 punch member to an extent substantially equal to the thickness of said strip and (3) being aligned with said slug receiving cavity and (4) having a punching portion on its projecting 5 end (a) said punching portion having a first surface disposed out of perpendicular relationship with the longitudinal extent of said punch element;

(b) said punching portion having a second surface disposed out of perpendicular relationship with the longitudinal extent of said body and in angular relationship with said first surface;

(0) and further having a chamfered portion interconnecting said first and second surfaces;

(d) said first surface being disposed in substantially parallel relationship to a plane extending normally to the periphery of said back-up member at the point of contact of said punch element and said strip material.

ness of said strip.

References Cited in the file of this patent UNITED STATES PATENTS 617,012 Grifiin Jan. 3, 1,199,193 Krauth Sept. 26, 1,670,317 Seymour May 22, 1,984,737 Gerster Dec. 18, 1,986,139 Cumfer Jan. 1, 2,185,885 Bruker et al Jan. 2, 2,287,168 Duncan June 23, 2,359,682 Ruder Oct. 3, 2,550,146 Gillich et al Apr. 24, 2,781,095 Spinner Feb. 12, 3,027,106 Brooks Mar. 27, 3,064,513 Hershey Nov. 20,

FOREIGN PATENTS 592,179 France Apr. 24, 

1. A SLOT CUTTING DEVICE FOR USE WITH CONTINUOUSLY ADVANCING STRIP MATERIAL, COMPRISING: (A) JUXTAPOSITIONED PUNCH AND BACK-UP MEMBERS (1) EACH HAVING ENDLESS PERIPHERAL EDGES THAT ARE ARRANGED FOR MOVEMENT AROUND PARALLEL AXES AND THROUGH CLOSED CYCLIC PATHS OF MOVEMENT THAT RESPECTIVELY INCLUDE INCREMENTS OF MOVEMENT THAT ARE SUBSTANTIALLY ADJACENT THE OPPOSED SURFACES OF SAID STRIP (A) WHEREBY SAID STRIP MAY PASS BETWEEN SAID PUNCH AND BACK-UP MEMBERS IN SUBSTANTIAL TANGENCY THEREWITH; (B) A SLUG RECEIVING CAVITY OPENING RADIALLY INWARDLY FROM THE PERIPHERAL EDGE OF SAID BACK-UP MEMBER; (C) AT LEAST ONE PUNCH ELEMENT (1) CARRIED BY SAID PUNCH MEMBER FOR MOVEMENT THEREWITH AND (2) PROJECTING BEYOND THE PERIPHERAL EDGE OF SAID PUNCH MEMBER TO AN EXTENT SUBSTANTIALLY EQUAL TO THE THICKNESS OF SAID STRIP AND (3) BEING ALIGNED WITH SAID SLUG RECEIVING CAVITY AND (4) HAVING A PUNCHING PORTION ON ITS PROJECTING END (A) SAID PUNCHING PORTION HAVING A FIRST SURFACE DISPOSED OUT OF PERPENDICULAR RELATIONSHIP WITH THE LONGITUDINAL EXTENT OF SAID PUNCH ELEMENT; (B) SAID PUNCHING PORTION HAVING A SECOND SURFACE DISPOSED OUT OF PERPENDICULAR RELATIONSHIP WITH THE LONGITUDINAL EXTENT OF SAID BODY AND IN ANGULAR RELATIONSHIP WITH SAID FIRST SURFACE; (C) AND FURTHER HAVING A CHAMFERED PORTION INTERCONNECTING SAID FIRST AND SECOND SURFACES; (D) SAID FIRST SURFACE BEING DISPOSED IN SUBSTANTIALLY PARALLEL RELATIONSHIP TO A PLANE EXTENDING NORMALLY TO THE PERIPHERY OF SAID BACK-UP MEMBER AT THE POINT OF CONTACT OF SAID PUNCH ELEMENT AND SAID STRIP MATERIAL. 